How do you multiply (8x + 9)(8x + 3) ?

Sep 11, 2017

$64 {x}^{2} + 96 x + 27$

Explanation:

We have,
$y = \left(8 x + 9\right) \left(8 x + 3\right)$

$\implies y = 8 x \left(8 x + 9\right) + 3 \left(8 x + 9\right)$

$\implies y = 64 {x}^{2} + 72 x + 24 x + 27$

Collect like terms

$y = 64 {x}^{2} + \left(72 x + 24 x\right) + 27$

$\implies y = 64 {x}^{2} + 96 x + 27$

Therefore,

$\left(8 x + 9\right) \left(8 x + 3\right) = 64 {x}^{2} + 96 x + 27$